We figured it was about time we put
together a Firefly Timeline. This is as accurate as we could make it,
and we will be sure to update it as new information becomes available.
We cite our sources for every date given, so you can judge the worth of
each piece of information. We should also mention that this is not the
only Firefly Timeline on the internet. An alternative timeline is Edgar Governo's Firefly Timeline.
The Governo timeline is mostly in agreement with the Signal's to within
a month, but there are minor differences in some of the less accurately
known dates.

Our intent in putting this together is that it may be of use to
anyone creating new Firefly content (which includes fanfic, audio dramas
and movies, or just RPG game sessions).

August 2459

Canonical event

Serenity (the ship) built by the Firefly Shipworks Ltd.

The Serenity Blueprints Reference Pack

Serenity's dedication plaque

20th September 2468

Canonical event

Mal born

Serenity (movie)

This information appears on the Operative's screen during the movie Serenity.

Unreliable!
Alliance records give more than one date for Mal's date of birth. In
addition to this detail (which would make Mal fifty years old at the
time of the movie), there is also a prop from the movie which lists
Mal's date of birth as both 27th March 2286 and 27th March 2486.

15th February 2484

Canonical event

Zoe born

Deleted scenes from the movie

This information appears on screen.

November ‒ December 2491

Canonical event

Simon born

Speculation based on age of actor

Simon's birthday occurs in the episode Out of Gas . The year is
speculation based on the age of child actor Zak Effron in the Safe
flashback.

19th December 2500

Canonical event

River born

From a prop used in the movie

Project Oracle records.

12th April 2506

In fan audio drama

Romana visits Shadow

Borderline

Borderline, season 1, episode 1

May ‒ July 2506

Canonical event

Pax released into the atmosphere of Miranda

Deduction

Educated guess, based on the assumption that it happened just before the war began.

May ‒ July 2506

Canonical event

The survey ship C57D lands on Miranda to find out what happened

Deduction

Mal says the report that they found on Miranda was "maybe twelve
years old". Exactly twelve years old would place this at November 2506
(assuming my date for the movie is correct). However, notice the word
"maybe" in the above. Mal is guessing. I consider it more likely is that
this took place before the war began.

Unreliable. Could have been any time between May 2506 and May 2507

June ‒ August 2506

Canonical event

The Unification war begins

The Serenity Visual Companion

The Serenity Visual Companion states that the war lasted "for
almost five years". We know that it ended in May/June 2511, so it must
have started around June/July/August 2506. I'm assuming here that if it
were any earlier, Joss would have said "five years", and that if it were
any later he would have said "four and a half years".

June 2506

In fan audio drama

Dark Places Teaser

Dark Places

Dark Places, episode 1: Vindicator

September 2506

Canonical event

Simon and River as children (flashback)

Safe

On screen caption during Safe places this as "eleven years ago". That is, eleven years before Safe.

The caption probably didn't mean exactly eleven years ago. More likely
it meant eleven years to the nearest year, in which case this date

could be up to six months out.

13th September 2506

In fan audio drama

Romana reports on Santo's dwindling tourist trade

Borderline

Borderline, season 1, episode 2

8th January 2507

In fan audio drama

Romana interviews a slave trader

Borderline

Borderline, season 1, episode 3

4th May 2507

In fan audio drama

Romana goes behind enemy lines

Borderline

Borderline, season 1, episode 4

16th August 2508

In fan audio drama

The (first) fall of Athens

Borderline

Borderline, season 1, episode 5

19th February 2509

In fan audio drama

Romana visits Jiangyin

Borderline

Borderline, season 1, episode 6

6th November 2509

In fan audio drama

Romana encounters a lynch mob

Borderline

Borderline, season 1, episode 7

18th July 2510

In fan audio drama

Evacuation of Shadow

Borderline

Borderline, season 1, episode 8

27th October 2510

In fan audio drama

Romana interviews refugees on Ezra

Borderline

Borderline, season 1, episode 9

April 2511

Canonical event

The battle of Serenity Valley begins

Deleted scenes from the movie

From a deleted scene in Serenity (the movie) we learn that the
battle lasted for seven weeks. Therefore the start date must have been
seven weeks before the end date, which we know to be May 2511.

April ‒ May 2511

Canonical event

Independents' high command surrenders

Deleted scenes from the movie

Source From a deleted scene in Serenity (the movie) we learn that
the high command surrendered two weeks before the end of the Battle of
Serenity Valley.

12th April 2511

In fan audio drama

Romana at the battle of Serenity Valley

Borderline

Borederline, season 1, episode 10

May 2511

Canonical event

The battle of Serenity Valley ends

Deleted scenes from the movie

The information appears briefly on a screen viewed by the Operative. You need a freeze frame to catch it.

May ‒ June 2511

Canonical event

The official end of the war - Unification Day

Bushwhacked

Alliance officer Harken says, "Some say after Serenity, the
Browncoats were through. That the war really ended in that valley." This
clearly implies that the war ended very soon after the Battle of
Serenity Valley.

June ‒ December 2511

Canonical event

River at school (flashback)

Serenity (movie)

From Serenity (the movie), this scene is set after the war.
Further, In the Serenity Visual companion, the shooting script for this
scene describes River as being ten years old during this scene, which
confirms that it must have taken place in 2511.

11th July 2511

In fan audio drama

Romana celebrates the end of the war

Borderline

Borderline, season 1, episode 11

15th January 2512

In fan audio drama

The Counterfeit Companion

Borderline

The Counterfeit Companion is the linking story connecting seasons 1 and 2 of Borderline.

29th February 2512

In fan audio drama

Elizabeth visits Serenity Valley

Borderline

Borderline, season 2, episode 1

4th September 2512

In fan audio drama

Elizabeth visits Santo

Borderline

Borderline, season 2, episode 1

2514

Canonical event

Mal buys Serenity

From a prop used in the movie

Mal's Alliance record

January ‒ February 2515

Canonical event

The Academy recruits River

The River Tam sessions

Educated guess based on the notion that this is set just before
River joins the academy, and on the assumption that the River Tam
sessions were approximately evenly distributed.

Additionally, in
Serenity (the pilot), Simon says River was 14 when she joined the
academy, so it cannot have been earlier than December 19th 2514. He also
says it was "months" before he started receiving coded letters, so it
cannot have been later than February 2515.

February ‒ March 2515

Canonical event

River requests a transfer

The River Tam sessions

Deduction based on the fact that this is set between River's
joining the Academy and River's writing to Simon, and on the assumption
that the River Tam sessions were approximately evenly distributed.

March ‒ April 2515

Canonical event

River starts sending coded messages to Simon

Serenity (episode)

Simon says he began receiving coded letters two years before being contacted by the underground.

June 2515

Canonical event

River going crazy

The River Tam sessions

Educated guess based on the assumption that the River Tam sessions were approximately evenly distributed.

August ‒ September 2516

Canonical event

Inara begins renting a shuttle on Serenity

The Train Job

During the episode The Train Job , Inara says she's been on board
for eight months. Therefore this event must have taken place eight
months before The Train Job .

March 2517

Canonical event

River knows Simon is looking for her

The River Tam sessions

Educated guess. This must have happened before Simon was contacted
by the underground, since River knew that Simon did not (yet) have
enough information to find her. But it must have happened quite late on,
because River has deduced Matthias's mission for her. Again, I make the
assumption that the River Tam sessions were approximately evenly
distributed.

March 2517

In fan audio drama

Simon discovers River's whereabouts.

Moonshine

Implicit, since this story is set just before Simon is contacted by the underground.

April 2517

Canonical event

Simon contacted by "some men" from "some underground movement" about River

Serenity (episode)

From Simon's explanation, this was two years after receiving coded
letters. In addition, this must have happened shortly before the rescue.

April ‒ May 2517

Canonical event

Simon rescues River from the Academy

Serenity (episode)

Deduction based on the notion that this can't have happened too long before Serenity (the pilot).

April 2517

In fan audio drama

Herren Island, Newhall, attacked by reavers

Dark Places

Dark Places, episode 1: Vindicator

May ‒ June 2517

Canonical event

Serenity (episode)

The Train Job

Deduction. Several clues in The Train Job indicate that the
interval between Serenity and The Train Job can have been a few days
at most (for example, River hasn't found out she's on a ship yet).

May ‒ June 2517

Canonical event

The Train Job

The Train Job

It is stated that exactly six years to the day have elapsed since the end of the Unification war.

July ‒ August 2517

Canonical event

Bushwhacked

Bushwhacked

It is stated ithat Inara has been on board Serenity for a few weeks
short of a year. Inara joined Serenity in August or September 2516.

August ‒ September 2517

Canonical event

Shindig

Deduction

Deduction based on the fact that Shindig and Safe must both have
occurred between Bushwhacked and Our Mrs Reynolds. In addition, it is
stated in Safe that three weeks elapsed between Shindig and Safe

September ‒ October 2517

Canonical event

Safe

Deduction

Deduction based on the fact that Shindig and Safe must both have
occurred between Bushwhacked and Our Mrs Reynolds. In addition, it is
stated in Safe that three weeks elapsed between Shindig and Safe

October 2517

Canonical event

Our Mrs Reynolds

Our Mrs Reynolds

Inara states that she has an appointment on October 24th. Mal
states that Serenity will take about a week to get there (which won't be
late), therefore this episode begins on October 17th 2517, or possibly a
few days earlier.

October ‒ November 2517

Canonical event

Jaynestown

Deduction

Deduction based on the fact that Jaynestown must have occured between Our Mrs Reynolds and Out of Gas.

November ‒ December 2517

Canonical event

Out of Gas

Deduction

Deduction based on the fact that Jaynestown, Out of Gas, Ariel and
War Stories must all have occured between Our Mrs Reynolds and Trash,
and on the notion that Simon's birthday (which happens in this episode)
occurred before River's. (I suspect that, if River's birthday had come
first, Simon would have got River a present, and then River would have
got Simon a present. This didn't happen.)

January ‒ February 2518

Canonical event

Ariel

Deduction

Deduction based on the fact that Ariel and War Stories must have occured between Out of Gas and Trash.

February ‒ March 2518

Canonical event

War Stories

Deduction

Deduction based on the fact that Jaynestown, Out of Gas, Ariel and
War Stories must all have occured between Our Mrs Reynolds and Trash.
In addition, Book's conversation with Simon at the start of War
Stories implies that Ariel was still very recent.

Late March

Canonical event

Trash

Trash

Mal tells Monty that he married "Bridget" (Saffron) about half a year back. Note that exactly half

a year would place this episode at April 2518 - however, Mal's

timekeeping is not that accurate. This episode must have taken place
earlier than April 2518, or there would not have been time for
subsequent episodes.

Late March

In fan movie

The Bellflower (movie)

Inside knowledge

The first episode of The Bellflower is stated by its creators to be set two weeks before The Message.

Early April

Canonical event

The Message

Deduction

Deduction based on the fact that The Message, Heart of Gold and
Objects in Space must have occured between Trash and (several months
before) Better Days

Late April

Canonical event

Heart of Gold

Deduction

Deduction based on the fact that The Message, Heart of Gold and
Objects in Space must have occured between Trash and (several months
before) Better Days

Early May

Canonical event

Objects in Space

Deduction

Deduction based on the fact that The Message, Heart of Gold and
Objects in Space must have occured between Trash and (several months
before) Better Days

Late May

In fan audio drama

Old Wounds

Old Wounds

Discussions between Mal and Kaylee regarding Serenity's primary
buffer panel on Old Wounds and Serenity (the movie) imply that Old
Wounds is set roughly six months before the movie.

June ‒ July 2518

Canonical event

Better Days

Deduction

Better Days must have occurred between Objects in Space and Those Left Behind.

August 2518

Canonical event

Those Left Behind

Deduction

Deduction based on the notion that Those Left Behind must occur about halfway between Objects in Space and the movie.

November 2518

Canonical event

Serenity (movie)

Serenity (movie)

Simon states that River is 17 years old, therefore this cannot have
taken place any later than December 18th 2518. In addition, sufficient
time must have elapsed between the end of the series and the movie to
allow for all the changes that have taken place. A widely accepted
"educated guess" for this period assumes the interval to have been six
months, which places the movie at November 2518.

The movie must
have taken place between June and early December of 2518 (and the June
limit is highly unlikely as this would only allow for a few weeks
between Trash and the movie).

Corroborating evidence is that, in the Serenity novelisation, author
Keith R. A. Decandido dates this as "eight years after the war". The war
ended in May/June 2511, so eight years later would be May/June 2519.
Since we already know that the movie must have taken place between June
and December 2518, this date cannot be accurate to the month. However if
we allow that it is accurate to the nearest year then this sets the
earliest possible date for the movie as seven and a half years after the
war, or November/December 2518.

December 2518

In fan audio drama

Wedding Day

Wedding Day

Information on the Sonic Cinema website reads: Set just after the
Serenity movie, Kaylee decides to go home to visit with her family for
Christmas

February 2519

In fan movie

Redemption

Inside knowledge

Browncoats: Redemption is stated (by its creator, in an interview with the Signal) to be set three months after Serenity the movie.